Q: How do I troubleshoot problem with my apple 24"display when attached to my macbook pro?

Recently, When I connect my laptop to the monitor the laptop changes as it normally does but a portion of the display blinks what should be there and then returns to black. My assumption is that the connector from the screen for video is faulty. The USB connector for sound works as it should- the sound moves from the laptop to the monitor. Is there something else that could be the problem? If so, how do I troubleshoot to determine the root cause?